Plural fluid turbine combining impulse and reaction blading



PLURAL FLUID TURBINE COMBINING IMPULSE AND REACTION BLADING Filed Nov.17, 1943 FIG.1.

FIG.3

@atented J W fiQ 2,ll35,i id2 runner. FLUD renames co PULSE REACTIUN B FApplication November 17, 1943, Serial No. 510,698

r In Sweden November 9, 1942 Section 1, Public Dew 690, August 8, 1946Patent expires November 9, 1962 5 Claims. (01.60-49) This inventionrelates to a turbine for expanding working fluids of diflerentpressures.

The invention has for its main object to effect as rapidly as possiblesuch a great decrease of the pressure of the high pressure fluids thatsaid blue driven by exhaust gases from an .internal combustion enginethat the turbine eillciency is practically independent of variations inthe load on the engine.

These and further objects are attained by constructions illustrated inthe annexed drawings.

in which:

Figure 1 is an axial section of an embodiment; Figs. 2 and 3 aresections of systems of nozzles or guide vanes and moving blade rims,these sections being taken on the lines 2 2 and 3-3, re-

spectively, in Fig. 1.

The turbines shown are intended to be driven by exhaust gases from aninternal combustion engine, said exhaust gases being supplied to theturbine at two or more different pressures.

The invention is based on the known fact that moving blades of theimpulse type require a considerably lower blade peripheral velocity thanblades of the reaction type. Consequently, if blade rims intended formotive fluids of high pressures are provided with moving blades of theimpulse type, and if blade rims for low pressure fluids are providedwith blades 01' the reaction type, a favourable turbine efiiciency canbe obtained both in the turbine portion driven by the high pressurefluid and in the portion driven by the low pressure fluid.

If the turbine is intended to be driven by exhaust gases from a motor,which exhaust gases are admitted at diflerent pressures, there existsanother reason for providing that portion of the turbine which is to becharged with low pressure gas, with moving blades of the reaction type.At

variations 0! the load on the motor, the drop-in temperature of the lowpressure gases is varying relatively more than the drop in temperatureof the high pressure gases. A reaction turbine is much less responsiveto such variations than an impulse turbine. Consequently, the eiliciencyof the reaction turbine is influenced to a small extent only byvariations in the load on the motor.

In-Fig. 1. there is shown embodiment of a turbine adapted to'be drivenby means or gases of are of the reaction type.

different pressures and having concentric admission means for the highpressure and low .pressure gases. Numeral l1 indicates the inlet for thelow pressure gases and iii the inlet for the highpressure gases. Saidinlets are separated from each other by means of a partition wall l9forming two admission chambers 20 and 2 I. 'The admission chamber 20 forthe low pressure gases is located outwardly of the admission chamber 2ifor the high pressure gases.

The high pressure gases are passing through a nozzle or guide vanesystem 22, a moving blade rim 23, a guide vane rim 24, and finallythrough a further movingblade rim 25 which is common to the highpressure and the low pressure gases. The last named gases are admittedto the moving blade rim 25 by means of a nozzle or. guide vane system26. The outlet from the turbine is indicated at 21.

As will be seen from Figs. 2 and 3, the moving blades of the blade rim23 are of the impulse type, while the moving blades of the blade rim Thehigh pressure gases are consequently working on a reaction blade systemin addition to an impulse blade system. The heat drop is divided amongstthe impulse blades and the reaction blades in a manner such that the gaspressure on the reaction blades common to. the high pressure and lowpressure gases will be substantially constant along the whole lengths ofthe blades, that is, the pressure prevailing in the intermediate space28 will be the same behind the impulse turbine portion and behind theguide vanes in the reaction turbine portion for the low pressure gases.Since the high pressure gases are passing two moving blade rims one ofwhich is provided with impulse blades, whereas the low pressure gasesare passing through one blade rim only having blades of the reactiontype, peripheral velocities will be obtained which ensure favourableeniciencies both for the low pressure portion and the high pressureportion of the turbine. v

The invention is obviously not limited to the. embodiment thereofdescribed and illustrated in the drawings, but may be modifled as toconstructional details within the scope of the appended claims.

What I claim is:

1. In an elastic fluid turbine, a turbine wheel. a first blade rimsystem including moving blades substantially of the impulse type, asecond blade rim system including moving blades substantially of thereactlontype, said moving blades being secured to said wheel, means foradmitting high pressure working fluid to said first blade rim system,and means for admitting low pressure working fiuid to said second bladerim system, said first system having a smaller mean diameter than saidsecond system, and the number of blade rims in said first system beinggreater than the number of blade rims in said second system, said bladerim systems being constructed and arranged to expand said high pressurefluid and said low pressure fluid, respectively, to substantially equalexhaust pressures.

2. In an elastic fluid turbine, a turbine wheel, a first blade rimsystem including moving blades substantially of the impulse type andmoving blades substantially of the reaction type disposed in seriesafter said impulse blades, a second blade rim system including movingblades substantially of the reaction type, said moving blades beingsecured to said wheel, means for admitting high pressure working fluidto said first blade rim system, and means for admitting low pressureworking fluid to said second blade rim system, said first system havinga smaller mean diameter than said second system, said blade rim systemsbeing constructed and arranged to expand said high pressure fluid andsaid low pressure fluid, respectively, to substantially equal exhaustpressures.

3. In an elastic fluid turbine, a turbine wheel, a first guide vane rim,a first moving blade rim having blades substantially of the impuisetype,a second guide vane rim, said rim being arranged in series in the ordernamed, a third guide vane rim located radially outwardly of said secondguide vane rim, a second moving blad rim having blades substantially ofthe reaction type and being adapted to receive working fluid from saidsecond and said third guide vane rims, means for admitting high pressureworking fluid to said first guide vane rim, and means for admitting lowpressure working fluid to said third guide vane rim, said blade rim,systems being constructed and arranged to expand said high pressurefluid and said low pressure fluid, respectively, to substantially equalexhaust pressures.

4. In an elastic fluid turbine, a turbine wheel, a first blade rimsystem including moving blades substantially of the impulse type andmoving blades substantially of the reaction type disposed in seriesafter said impulse blades, a second blade rim system including movingblades substantial- 1y oi the reaction type, said moving blades beingsecured to said wheel, means -for admitting high pressure working fluidto saidfirst blade rim system, and means for admitting low pressureworking fiuid to said second blade rim system, said second blade systemhaving its reaction blades common to the high pressure and low pressureworking fluids, said blade rim systems being constructed and arranged toexpand said high pressure fluid and said low pressure fluid,respectively, to substantially equal exhaust pressures.

5. In an elastic fluid turbine, a turbine wheel, a first blade rimsystem on said rotor including moving blades substantially of th impulsetype and spaced moving blades substantially of the reaction type, aguide vane disposed in the space between said moving blades, a secondblade rim system on said wheel including a second guid vane, saidreaction type moving blades registering with said second guide vane soas to be common to both systems, means for admitting pressure workingfluid to said first blade rim system, and means for admitting pressureworking fluid to said second blade rim system, said blade rim systemsbeing constructed and arranged to expand said high pressure fluid andsaid low pressure fluid, respectivel,y to substantially equal exhaustpressures.

JOHAN ERIK JOHANSSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 9 1,012,813 Chaleil Dec. 26, 19111,263,473 Schellens Apr. 23, 1918 1,428,925 Thomas Sept. 12, 19221,708,402 Schilling Apr. 9, 1929 2,258,794 Way Oct. 14, 1941 FOREIGN,PATENTS Number Country Date 225,820 Great Britain Apr. 30, 1925 229,641Great Britain Oct. 15, 1925 504,263 Great Britain Apr. 21, 1939 591,491France Apr. 10, 1925 781,103 France Feb. 18, 1935

